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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?7Y5q9CYF9jSbF8+avFvYMjUbmSBUK66ilAqrFwIQpWCiUbF5s7rg4N8IzdN/?= =?us-ascii?Q?ntr1thv5+aTXURp6z5qQystN4SKp9Mrc/66B5gf4KrXJ1G5g1HMHlilJl8KT?= =?us-ascii?Q?iBkkU4hK144lBm6b5ptf+dzqvEThizkL6ZU55lFh59CIBji4rikWBGKmt/vg?= =?us-ascii?Q?LO1FM97tzUoI9r7i9CHR2v1C5/oDs0U4EPTRnCwO/H6rk/fpjD46lm+UGSl5?= =?us-ascii?Q?hjrblO9u3RcKjrmKFca1M0thIAtZSYFUlhTPGq+62uoqyRAAgt3numvLjJCM?= =?us-ascii?Q?787b8x4iR2WknPrldEQbT0sWcTtwPia7cuPf7bgW6btV6ZeDmlQPVqMcAzq7?= =?us-ascii?Q?4TcBwir24I3qeoTtJRpOlxXdI1CA1GpKhlGGgkGGEyfJWKbBTw5X+7m6Ayxv?= =?us-ascii?Q?NYw837jxT+iQYZinhLn75dowNsfAqkpgv4MXPzVEmQ86XH0TFxPTnIcjtifF?= =?us-ascii?Q?9KBhGPgYy+q2CsQCjudB+FtF8sul+1XhG1urTBeEkkRx1fwB9OzMcoHeBq9P?= =?us-ascii?Q?05bq73VhD+VhOzRwshneZ5b7seAQqb+qnKpKD6pzUmHu0F1UFQ8M2y90z0V6?= =?us-ascii?Q?HWKjl6CMapdt0qhp7szYbN4xWte2ntmwBDaziB9hLIAXyuJD47YxuZkEcRHT?= =?us-ascii?Q?rYSE1zhwXvCL7Vb2vCI6U+nZR9EJiqXG+7cd/+1WeBk8LB/cJzIuY3kavslh?= =?us-ascii?Q?3r92lxnRlEuCS5A3+wgIt81XaSaFRit7OKxEtUi3RBQqbJrHWemhdSvSq8MH?= =?us-ascii?Q?x4PC6VFnChWY/Yk+wGbG/6bsfLGNCbEaTbqIKb8+e9hWeT5JY0A0jZbmuiuQ?= =?us-ascii?Q?uhzPwXY6HkQEDeMY4w9g3PrLhR6uajUhjDPTlwJnQcXoAS5hvPn8aAiQTULy?= =?us-ascii?Q?ibkHRAskXRH+9ICapPxKUdTNHLosMcBBTcq1yUZw9zpTrBwd3IBV4by3JeDg?= =?us-ascii?Q?GPR3/Y+97BVBa4SfqEzmUclRzxBswV5g7mgcC2eTfe8LcW5xevHKO0lNi6cR?= =?us-ascii?Q?pWmxaDQrRP8qy7DkZ536RVaSjjyFmth49+jiCTKFWcNPPPA91Ydm8qmNVAJl?= =?us-ascii?Q?LzDxCYuoJ4swJM6Yot9ZFAQMqx8t++qEi7Vm+rWUrDFZ9p2xgzXnsDPvvXpK?= =?us-ascii?Q?JCDjMrWFty35U8ujjVsK3JsMmIu3hYjNfmYwnS9fkETsougozt5076UsNgmV?= =?us-ascii?Q?qAdNd6izy9RPB6WD8rv9gutWIe8x5shYOOwMAkEgzvtYJkX8P8FLj16kGfN8?= =?us-ascii?Q?8I6eHRykXpvuJgeIhK8QywdgQy7+O0KCaKEfZEls2wf5ZYv1gJe9/iuBWAn2?= =?us-ascii?Q?4vKp0+kfhmYGYXIF15rCpL2Gr9XX7c95/fHd67yH+mf5fZR4hlljBxzI2vcS?= =?us-ascii?Q?qYUk/W4Eli0Pb47NOIRNtRvda1EuJWnKNzaoYmnmG59UZ6Kt2CM6C/vMCDhK?= =?us-ascii?Q?B2mwAE93l28p+AhiOlga6D7Pqs5zHttS2GltnGPTabICmzd8HHEJ8xrEV7kl?= =?us-ascii?Q?oOeqNHMpheV5jadeA9ITPUCLmWL+nFKEuzPi5ReHR86994JWXlMn75/59t3O?= =?us-ascii?Q?Na8TlUPFmzzK3Oq/ss83pqraFCtlqJ6ZHtBiqvJr?= X-MS-Exchange-CrossTenant-Network-Message-Id: 07cec82c-f599-413f-1f59-08dab43f569a X-MS-Exchange-CrossTenant-AuthSource: MN0PR11MB6206.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Oct 2022 15:08:55.8351 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: fDOglhghSJl5YVhIlH27Xm81x4wU6K7TIS/n8vu8zM+9ahzF4RRiUCb1k6u6CwdiF/vK09XK5fuXl5WRVJ6msw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR11MB4635 X-OriginatorOrg: intel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vincent, On 2022-09-25 at 16:39:05 +0200, Vincent Guittot wrote: [...] > +static long wakeup_latency_gran(struct sched_entity *curr, struct sched_entity *se) > +{ > + long latency_offset = se->latency_offset; > + > + /* > + * A negative latency offset means that the sched_entity has latency > + * requirement that needs to be evaluated versus other entity. > + * Otherwise, use the latency weight to evaluate how much scheduling > + * delay is acceptable by se. > + */ > + if ((se->latency_offset < 0) || (curr->latency_offset < 0)) Maybe use latency_offset < 0 directly? BTW, is it the policy that requires the user to provide a negative latency nice so as to tell the kernel to compare between two tasks? Maybe I missed the scenario, I'm thinking of the reason why we used " || " rather than " && " above. To be more specific, why not comparing se and curr only when they both have high requirement on latency(negative)? The benefit of using "||" I'm thinking of is that, if se->latency_offset < 0 and curr->latency_offset > 0, the latency_offset would be even smaller than se->latency_offset, which will make the preemption easier. And vice verse. thanks, Chenyu > + latency_offset -= curr->latency_offset; > + > + return latency_offset; > +}